Molding electrodes.



G. FAVIER.

MOLDING ELECTRODES. APPLICATION FILED APR. 15. 1914.

1,150,021. Ptented Aug. 17, 1915.

2 SHETSSHEET I.

L w L j I VE/ITOR C fl- ATTORNEY G. FAVIER.

MOLDING ELECTRODES. APPLICATION r1120 "11.15. 1914.

1,150,021. Patented Aug. 17,1915.

2 SHEETS-SHEET 2.

' WITNESSES UNITED STATES PATENT OFFICE.

GEORGES FAVIER, OF SUSPENSION BRIDGE, NEW YORK.

.MOLDING ELECTRODES.-

To all whom it may concern Be it known that I, GEoncEs Fxvnzn, a citizenof the Republic of France, residing in Suspension Bridge, New York, haveinvented certain new and useful Improvements in Molding Electrodes, ofwhich the following is a specification.

This invention aims to provide certain improvements whereby electrodesof large sizes and of great length can be made with comparatively littledifiiculty and of a desired composition throughout their cross-sectionat a low cost.

My process involves two principal points of improvement and certainimprovements in detail which are referred to at length hereinafter. Thetwo principal points of improvement are the progressive pressing of theelectrode paste as the length of the pressed portion graduallyincreases, the pressing being'prefera-bly effected by means of rollersworking on the interior portion of the cross-section as well as on theouter portion; and second, the employment of special pastes which makethe central portion of the electrode spongy or porous during thesubsequent baking or burning thereof and which greatly facilitates suchburning, the pastes being preferably graduated so as to increase theporosity gradually from the outer portion toward the center.

The'accompanyin drawings illustrate a suitable machine or carrying outthe process. I a

'Figure 1 1s a vertlcal diametral section through the mold and adjacentparts, showing the parts within the mold in elevation;

1 Figs. 2, 3, 4 and 5 are respectively horizontalsections on thesimilarly numbered lines in Fig. 1 the outer casing being omitted fromFig. 4:. Fig. 6 is partly a longitudinal section and partly an elevationof an electrode made in accordance with this invention.

These large electrodes are used chiefly in metallurgical furnaces, butmay be used in other classes of electrical apparatus.

Referring to the apparatus illustrated, a mold A of cylindrical orsimilar shape is mounted at its lower end upon a horizontal base Bsupported upon balls C an d upon a,

pivot D and rotated continuously by means of a worm gear E driven by amotor F. The mold may be divided into four or any other desired numberof segments fastened together by means of vertical flanges GSpecification of Letters Patent.

Patented Aug. 17, 1915.

Application filed April 15, 1914. Serial No. 832,007.

mounted thereon and bolted together as indicated in Fig. 5. At its lowerend the mold is mounted on the base B by means of a similar flange H. Atits upper end themold is held in a suitable opening in the floor J whichcarries a pair of guides K connected by a cross beam L for a purposehereinafter explained. At the center of the mold there is fixed a roundwooden rod M fastened to the base B and extending upward clear to thecross beam L. This rod serves to guide the pressing rollers and alsoforms the center of the completed electrode.

- The compressing of the paste of which the electrode is to be formed isaccomplished by means of rollers such for example as the three rollersN, N and N The roller N covers substantially the middle third of thespace between the central rod M and the mold; and the rollers N and Ncover respectively the inner and the outer third of such space. Theserollers may be polygonal indicated or may be circular or may be of anyother desired shape, and are preferably smaller at their inner ends tocompensate for the comparatively slower rate of movement as the rollersrotate about the rod M.

The rollers are mounted in arms 0, O on.

the lower end of a tube P which surrounds the rod M freely. The tube Pextends up avard above the floor J and carries arms Q,

the ends of which embrace the guides K 50 as to prevent rotation of thetube P. Thus as the base B- and mold A are rotated the lady and iscompacted bythe relative movement of the rollers thereon. As thequantity of molded paste increases the rollers continually ride on thetop and, therefore, rise slowly, carrying with them the entire frame P,Q on which they are mounted. There is thus produced a very thoroughcompacting of the paste throughout the cross section and throughout theheight of the electrode. The paste may be fed into the mold in variousways'and by various means using the above described method of compactingit uniformly and making it' of any desired height. I prefer, however,.to

"the electrode.

feed the paste in the particular way hereinafter described. I feedseveral different compositions of paste at different. points between thecenter and the outer surface of Preferably three different pastes areused and each is fed just in advance of one of the respective rollers N,N and N so as to produce a plurality of roughly outlined concentriczones or rings 10, 11 and 12 (Figs. 1 and 5) of differing materialsgraded toward the center. The paste which is fed just in front of theoutermost roller N is the purest graphite or similar conductingmaterial. The pastefed in front of the intermediate roller N is amixture of the paste used for the outermost ring with saw dust orsimilar material which will burn out during the burning of the electrodeand will render the latter more or less spongy so as to facilitate theescape of the gases produced in the burning and thus permit a very quickand a very regular burning, which in turn produces an economy of timeand of fuel. In front of the innermost roller N there is fed a pastecontaining a still greater proportion of saw dust or the like. Thus anelectrode of increasing porosity toward the center is produced. At thesame time the distribution of the material is very regular andsubstantially the same throughout the cross section at all points in theheight. The wooden rod M is converted into charcoal during the firstmoments of the burning of the electrode and by reason. of the greatporosity of such charcoal it forms practically a chimney for the escapebrackets S carried by the tube P and provided at their upper ends withhoppers T into which the material is fed at a rate which is uniform forthe three hoppers. These hoppers are located'just above a platform Uwhich covers the top of the mold and facilitates access of the workmento the feed hoppers. The platform U rests on the floor J and has a.central ring V surrounding the tube P and through which this tube risesas the height of the molded electrode increases. The pipes R, R and Rare made in sections of any desired length, say three feet, united bycouplings .W. When the feeding has continued sufficiently to bring thehoppers- T more. than three feet above the platform then the uppermostsection of each feed pipe may betaken off and the hoppers may be appliedto the next sections of the pipe so as to keep the hoppers within reachof the workmen on the platform U.

Though I have described with great particularity of 'detaila certainapparatus yet it will be understood that various styles of apparatus maybe used for carrying out my improved process. The rollers are preferablyof truncated pyramidal shapes in order to effect a certain amalgamationof the paste, but they may be conical or otherwise shaped. They may besolid or hollow or of practically any composition, though I prefer thattheir external portions shall contain some copper because this metaldoes not adhere strongly to the paste. Of course, it is only necessaryto have a relative movement other circumstances andtheir shape may bevaried. Likewise the number of rings of paste of different compositionsmay .be greater or less than th three described and their compositionsmay also be different from those described. The paste may be fed eitherby hand or by any usual or suitable mechanism for feeding regularquantities of such materials. The wooden rod at the center may be madeof greater or less size depending on the size of the electrode and uponthe composition of the paste and the expected volume of gases generatedin the paste during burning. There is no great amount of strain on thisrod and it may be entirely omitted, especially in electrodes ofcomparatively small diameter and other means used for holding theroller-supporting frame centrally of the mold.

A portion of an electrode 13 molded according to this invention and thenburned in the usual way is shown in Fig. 6.

It will thus be seen that by this process we can make electrodes of anydesired diameter and of any desired. length with ,no

practical difficulties and that such electrodes may be molded of anyinternal composition. It will also be seen that the molded electrodewill be of the greatest homo eneity and will permit an economical anrapid burning and when burned will possess in the highest degree thevirtues of conductibility and great regularity and will be practicallywithout cracks or similar defects.

The burning referred to is necessary for all electrodes in order toeliminate volatile particles or gases. With electrodes molded in the oldway of uniform density it has not been possible in all cases to effect acomplete tion of the furnace as well as losing the electrode. In burningan electrode of one meter diameter for example, supposing it molded inthe' old way of uniform density, the heat Will penetrate very slowlyfrom the outside toward the center and the distillation will generallybe imperfect in the center, and there will be occasional surfaceirregularities due to the escape of gases outward suddenly at particularpoints; whereas in burning an'electrode molded according to thisinvention, the more porous center will liberate its gases more freely,so as to compensate in a measure for the slower heating of the interior;and with a wooden core, which is quickly converted to charcoal, the heatwill have quick access and the distillation products an easy exit fromthe central part of the electrode. Thus electrodes of this character canbe burned more rapidly and more cheaply and will be found of a moreuniformly good quality than those heretofore known.

What I claim is- 1. In the manufacture of electrodes the method whichconsists inmolding the electrode of different compositions arranged inconcentric zones, the inner zone having a greater percentage-ofcombustible material n combustible material whereby the inner ascomposition, and then burning the zone is rendered more porous than theouter zone.

2. A11 electrode comprising concentric zones of material of increasingporosity toward the center. 3. An electrode comprising concentric zonesof material ofincreasing porosity toward the center, the particles ofone zone being intermingled with those of the next to form a unitarystructure.

4. An electrode comprising concentric zones of material of increasingporosity toward the center, the outer zone being of the most highlyconductive material and the center being of charcoal.

5. An electrode comprising concentric zones of material of increasingporosity toward the center,'the outer zone being of the most highlyconductive material 6. An electrode comprising concentric zones ofmaterial of increasing porosity towazid the center, the center .being ofcharcoa In Witness whereof, I .have hereunto signed my name in thepresence of two subscribing witnesses.

GEORGES FAVIER.

Witnesses:

. ANDREW THOMPSON,

PAUL MORRIS.

